The Folding Funnel Landscape of the Peptide Met-enkephalinWe study the free energy landscape of the small peptide Met-enkephalin. Our data were obtained from a generalized-ensemble Monte Carlo simulation taking the interactions among all atoms into account.…U. H. E. Hansmann, Y. Okamoto, J. Onuchic·Oct 29, 1998SaveLearn
Electronic Structure Methods Exhibiting Linear Scaling of the Computational Effort with Respect to the Size of the SystemMethods exhibiting linear scaling with respect to the size of the system, so called O(N) methods, are an essential tool for the calculation of the electronic structure of large systems containing…Stefan Goedecker·Oct 29, 1998SaveLearn
Theory of Doping and Defects in III-V NitridesDoping problems in GaN and in AlGaN alloys are addressed on the basis of state-of-the-art first-principles calculations. For n-type doping we find that nitrogen vacancies are too high in energy to be…Chris G. van de Walle, Catherine Stampfl, Joerg Neugebauer·Oct 28, 1998SaveLearn
Irreversibility from a Reversible EquationAfter a discussion on the state of local equilibrium with temperature inhomogeneity, comparing mixture state reprsentation in statistical mechanics and pure state representation in thermo field…Hiroshi Ezawa, Koichi Nakamura, Keiji Watanabe·Oct 28, 1998SaveLearn
Normal state properties of an interacting large polaron gasA simple approach to the many-polaron problem for both weak and intermediate electron-phonon coupling and valid for densities much smaller than those typical of metals is presented. Within the model…G. De Filippis, V. Cataudella, G. Iadonisi·Oct 27, 1998SaveLearn
Spin relaxation of conduction electrons in polyvalent metals: A realistic calculationRelaxation of electronic spins in metals is significantly enhanced whenever a Fermi surface crosses Brillouin zone boundaries, special symmetry points, or lines of accidental degeneracy. A realistic…J. Fabian, S. Das Sarma·Oct 27, 1998SaveLearn
Complex periodic potentials with real band spectraThis paper demonstrates that complex PT-symmetric periodic potentials possess real band spectra. However, there are significant qualitative differences in the band structure for these potentials when…Carl M. Bender, Gerald V. Dunne, Peter N. Meisinger·Oct 27, 1998SaveLearn
Comment on ``On loss of quantum coherence in an interacting Fermi gas'' (cond-mat/9810297)In a recent paper EH Eriksen and Hedegard (EH) claimed that they ``clarified'' our path integral calculation GZ1 and found an error in our analysis. Here we will demonstrate…Dmitrii S. Golubev, Andrei D. Zaikin·Oct 27, 1998SaveLearn
Novel Transport Mechanism for Interacting Electrons in Disordered Systems: Variable-Range Resonant TunnelingTo interpret recent experimental observations of the phononless hopping conduction, we suggest a novel transport mechanism according to which the current-carrying single electrons move via quantum…S. D. Baranovskii, I. S. Shlimak·Oct 27, 1998SaveLearn
Finite-size scaling of helix-coil transitions in poly-alanine studied by multicanonical simulationsWe report results from multicanonical simulations of poly-alanine. Homopolymers of up to 30 amino acids were considered and various thermodynamic quantities as a function of temperature calculated.…U. H. E. Hansmann, Y. Okamoto·Oct 27, 1998SaveLearn
An exact representation of the fermion dynamics in terms of Poisson processes and its connection with Monte Carlo algorithmsWe present a simple derivation of a Feynman-Kac type formula to study fermionic systems. In this approach the real time or the imaginary time dynamics is expressed in terms of the evolution of a…Matteo Beccaria, Carlo Presilla, Gian Fabrizio De Angelis et al.·Oct 26, 1998SaveLearn
Disorder effects and electronic conductance in metallic carbon nanotubesDisorder effects on the density of states and electronic conduction in metallic carbon nanotubes are analyzed by a tight binding model with Gaussian bond disorder. Metallic armchair and zigzag…K. Harigaya·Oct 26, 1998SaveLearn
Long-range coherence and mesoscopic transport in N-S metallic structuresWe review the mesoscopic transport in a diffusive proximity superconductor made of a normal metal (N) in metallic contact with a superconductor (S). The Andreev reflection of electrons on the N-S…H. Courtois, Ph. Gandit, B. Pannetier et al.·Oct 26, 1998SaveLearn
Quantum Relaxation of Ensembles of NanomagnetsRecent theory and experiment in crystals of molecular magnets suggest that fundamental tests of the decoherence mechanisms of macroscopic quantum phenomena may be feasible in these systems (which are…N. V. Prokof'ev, P. C. E. Stamp·Oct 26, 1998SaveLearn
Quantum Environments: Spin Baths, Oscillator Baths, and applications to Quantum MagnetismThe low-energy physics of systems coupled to their surroundings is understood by truncating to effective Hamiltonians; these tend to reduce to a few canonical forms, involving coupling to…P. C. E. Stamp·Oct 26, 1998SaveLearn
Short Time Quantum AC response of a system of NanomagnetsWe calculate the magnetisation relaxation in the short-time regime for an ensemble of nanomagnets in the presence of a low-frequency external AC biasing field, at temperatures lower than the magnetic…G. Rose, P. C. E. Stamp·Oct 26, 1998SaveLearn
Quantum-Mechanical Position Operator and Localization in Extended SystemsWe introduce a fundamental complex quantity, zL, which allows us to discriminate between a conducting and non-conducting thermodynamic phase in extended quantum systems. Its phase can be related…A. A. Aligia, G. Ortiz·Oct 26, 1998SaveLearn
Quantum mechanics with coordinate-dependent massWe study a motion of quantum particles, whose properties depend on one coordinate so that they can move freely in the perpendicular direction. A rotationally-symmetric Hamiltonian is derived and…A. V. Kolesnikov, A. P. Silin·Oct 26, 1998SaveLearn
Stability of the vortex lattice in D-wave superconductorsUse is made of Onsager's hydrodynamic equation to derive the vibration spectrum of the vortex lattice in d-wave superconductor. In particular the rhombic lattice (i.e. the 45 tilted…J. Shiraishi, M. Kohmoto, K. Maki·Oct 26, 1998SaveLearn
Orbital Magnetism in Disordered Mesoscopic MetalsThe theory of orbital magnetism in disordered metals is reviewed, and extended to include a broad range of temperatures and fields. Sample-to-sample fluctuations in the orbital magnetic…B. Shapiro·Oct 25, 1998SaveLearn
Temperature dependence of the diffuse scattering fine structure in equiatomic CuAuThe temperature dependence of the diffuse scattering fine structure from disordered equiatomic CuAu was studied using in situ x-ray scattering. In contrast to Cu3Au the diffuse peak…O. Malis, K. F. Ludwig,, W. Schweika et al.·Oct 23, 1998SaveLearn
New solutions to the Reflection Equation and the projecting methodNew integrable boundary conditions for integrable quantum systems can be constructed by tuning of scattering phases due to reflection at a boundary and an adjacent impurity and subsequent projection…Holger Frahm, Nikita A. Slavnov·Oct 23, 1998SaveLearn
Computing Number FluctuationsHere we try and delienate the properties of the function that corresponds to fluctuations in the momentum distribution. The quantity denoted by N(k,k') is quite an interesting object. It…Girish S. Setlur, Yia-Chung Chang·Oct 23, 1998SaveLearn
Bloch function description of a Bose-Einstein condensate in a finite optical latticeWe consider stationary and propagating solutions for a Bose-Einstein condensate in a periodic optical potential with an additional confining optical or magnetic potential. Using an effective mass…M. J. Steel, Weiping Zhang·Oct 22, 1998SaveLearn
Competition of Ferromagnetic and Antiferromagnetic Order in the Spin-1/2 XXZ Chain at Finite TemperatureAn analytical study is presented of the crossover in the gapless attractive XXZ chain from antiferromagnetic to ferromagnetic behaviour at low to high temperature, respectively. In particular, an…K. Fabricius, A. Klümper, B. M. McCoy·Oct 21, 1998SaveLearn